Verifying Keg Cleanliness

[Shortbus901]

Hi all, I'm wondering if anyone has any tips on QA/QC procedures for draft product? I've tried plating samples before but between the Sanke tap, hose and picnic faucet I just don't have much confidence in the results. Of the breweries I have talked to, most simply do some sensory testing and let it go at that. Most of those guys have automated kegging lines and stainless kegs though. We are using a mix of plastic (PKA) and stainless kegs with a 3 tap keg washer and a hose octopus coming off the brite.

Recently our keg washer malfunctioned leading to an unknown number of kegs not being washed or sanitized before being filled. We are working up a set of procedures for verifying that the machine is working properly throughout a keg washing "session" as well as keeping better track of the preventative maintenance on the washer. I'm just wondering if anyone else has any additional ideas we could implement. Thanks in advance!

[Larry Doyle]

We had a highly automated Sankey system. In addition to periodic micro plating we used to check the residual water (condensate) that remained in the keg before filling. We were checking for an excessive amount of residual (max was 200 mls in a half bbl; normal was around 100 mls) and also for any abnormalities in the water that could indicate a problem.
On a weekly basis we also printed out a graph of the wash cycle for each head. That's probably not possible with your setup.
I never used but have seen a test keg with a plexiglass window to observe the cleaning process.

[drewseslu]

Pulling spears

It is much easier if you happen to have even some kegs with threaded spears, but just periodically pulling spears and inspecting can go a long way.

[Junkyard]

It is much easier if you happen to have even some kegs with threaded spears, but just periodically pulling spears and inspecting can go a long way.

No need for threaded spears. We wash, sanitize, and fill all of our kegs by taking the spears out.
Removing or replacing a spear is very simple, and can be done in a matter of seconds. It obviously doesnt make sense for a bigger brewery to fill kegs this way, but If you we're going to do a random check before the keg got filled it might make sense.

[CraftBeerIndia]

sampling plan

I guess you would want to include your kegs as part of your overall "sampling plan".
set aside 2-5% of kegs (from random points in the run ie beginning, middle, end...) after the keg washer to verify that your cleaning regime is effective.
take the spears out. pour out the rinse water from the keg. measure it.
set your CCP critical control parameter based on an average of what you measure...
say 50-100mL of rinse water on average should be acceptable.
visually inspect the kegs with a flashlight (a small dentist's mirror helps look inside)
look for scale, particles, debris, etc...
plate the rinse water. set a CCP for number of CFUs
you can use WLN for aerobic and Raka Ray for anaerobic
alternatively using ATP you can set up a pass/fail and get results within 10 seconds.
I would also include your process gasses into your sampling plan as well (ie compressed air being used in keg cleaning).
And i assume your water source into the keg washer is already part of your sampling plan...?

What are other people out there doing? I'd be interested to know any other opinions.

[tariq khan]

Keg inspection

It is much easier if you happen to have even some kegs with threaded spears, but just periodically pulling spears and inspecting can go a long way.

My only issue with pulling spears out is the safety factor, I'm comfortable doing it myself and making sure the keg has been de-gassed, however I've experienced on three occasions, an operative perhaps distracted nearly taking his head off after trying to remove a spear from a charged up keg.

T

[Shortbus901]

My only issue with pulling spears out is the safety factor, I'm comfortable doing it myself and making sure the keg has been de-gassed, however I've experienced on three occasions, an operative perhaps distracted nearly taking his head off after trying to remove a spear from a charged up keg.

T

This is my concern as well. Once the PKA spears are unscrewed they generally can't be put back in without leaking so the keg is lost.

We have pulled a few and tested the residual rinse water with the ATP meter. Worked well determining which kegs were not cleaned when the machine failed but again, during regular production it requires removing the spear and or destruction of the keg.

The solution for now has been to stick to a stringent protocol for monitoring the wash/rinse/sanitize cycle and have the guys checking the discharge liquid for cleanliness and chemical concentration on a regular basis and recording the results.

[BenBailey]

Keg Micro Sampling Method

Justin,

I don't have any experience with the plastic kegs, but I do know of a good way to check your beer in a stainless keg without sacrificing the entire fill. We plate a keg after being filled with beer by using a stainless sankey fitting which has a Perlick sample valve on top. We plugged the gas side with a blank disc and a beer nut. We wrap this setup in an autoclave bag and then sterilize it in the autoclave before sampling. If you talk to Mark Hobler at Perlick, he can set you up with what you need.
We then take a keg after it has been filled with beer and lay it on its side. Then we whack it on the side with a dead blow hammer to raise the pressure. We spray the keg's fitting down with 70% Iso-Propyl and then connect the autoclaved sankey-sample valve. Then aseptically sample the beer into a sterile recepticle and plate as you normally would. Keep in mind that you will only get foam out of the keg, so collect at least twice the volume that you want to plate. We only take about 250 ml out of the keg (or 500 ml of foam).
Ben Bailey
QA Manager
Troegs Brewing Co.

[Woolsocks]

keg safety

Not to thread-jack, but see elsewhere about the safety issues with PKA kegs - they've been exploding pretty often.

[timroberts]

Rotech Keg

Recently we had Chris Nimptsch from Profamo Inc. come in with a Rotech keg which measures temp, pressure, and volumes throughout the cleaning/sanitizing/filling process. It wasn't really that cheap, and I think it would be a lot less valuable if your racker is not at all automated, but for many I would HIGHLY recommend looking into this service.

Tim Roberts
Head Brewer
Yards Brewing Company
timroberts@yardsbrewing.com

[MJMurphy]

My only issue with pulling spears out is the safety factor, I'm comfortable doing it myself and making sure the keg has been de-gassed, however I've experienced on three occasions, an operative perhaps distracted nearly taking his head off after trying to remove a spear from a charged up keg.

T

From a safety perspective, please invest in a proper keg spear removal tool. There's just no reason to get seriously hurt over beer. The proper tool will vent the keg before allowing you to pull the locking ring.

On the QC side we have followed the steps outlined by Ben Bailey and CraftBeerIndia. We also ran some audits where we would open and inspect 10 kegs then run them through the cleaning cycle and re-inspect. We also alternate out chemical between an acid-based cleaner and caustic, 1 month of acid every four months. We don't have a way to really track our float turnover, so we just alternate. If you have an idea of how often you turn over your kegs you could set up a more acurate schedule.

We have a two head racker and are considering the Rotech keg assessment. We probably won't go in for our own unit, but the service sounds like a great idea. For all the work we put into making our beer, its important that it makes it to the tap with the same care and quality.

Matthew

[Junkyard]

all you need to remove a spear is a small flat head screwdriver and a sanke tap. Vent the co2 then take the snap ring out and pull the spear. not rocket science. People who take their heads off with spears probably arent smart enough to be in the brewing industry and should consider a completely safe desk job or something. If you try to take the snap ring out without the keg being degassed it will start hissing loudly... probably an indication that the keg is under pressure.

my 2 cents